Use case diagrams typically represent the context of a system and system requirements. Usually, you begin at a high level and specify the main use cases of the system. Next, you determine the main system use cases at a more granular level. As an example, a "Conduct Business" use case can have another level of detail that includes use cases such as "Enter Customers" and "Enter Sales". Once you have achieved the desired level of granularity, it is useful to have a convenient method of expanding or contracting the use cases to grasp the scope and relationships of the system's use case views.
The hyperlinking feature of Together allows you to create browse-through sequences comprised of any number of use case (or any other) diagrams. You can link entire diagrams at one level of detail to the next diagram up or down in a sequence of increasing granularity, or you can link from key use cases or actors to the next diagram. By browsing the hyperlink sequence, you can follow the relationships between the use case diagrams.
Together does not confine hyperlinking to such sequences, however. You can use hyperlinking to link diagrams and elements based on your requirements. For example, you can create a hierarchical browse-through sequence of use case diagrams, creating hyperlinks within the diagrams that follow a specific actor through all use cases that reference the actor.
To learn how to create and browse hyperlinks, see Hyperlinking Diagrams.